1. Technical Field
This disclosure relates generally to flow batteries and, in particular, to a system and method for sensing and mitigating hydrogen evolution within a flow battery system.
2. Background Information
A typical flow battery system includes a flow battery stack, an anolyte reservoir and a catholyte reservoir. An anolyte solution is circulated between the anolyte reservoir and the flow battery stack. A catholyte solution is circulated between the catholyte reservoir and the flow battery stack.
During operation, the flow battery stack may convert electrical energy into chemical energy, and store the chemical energy in the anolyte and catholyte solutions. Hydrogen evolution within the anolyte solution, however, may also occur as the electrical energy is being converted to chemical energy. The term “hydrogen evolution” describes a secondary reaction where positively charged hydrogen ions combine with negatively charged electrons to form hydrogen gas. The formation of hydrogen within the anolyte solution may decrease system efficiency and may also create an imbalance between the states of charge of the anolyte and catholyte solutions. It also may result in unsustainable changes to the composition of the solutions, which may require these solutions to be replenished. There is a need for a system and method for sensing and mitigating hydrogen evolution within a flow battery system.